北半球夏季的斜压波包个例分析

A Case Study of Baroclinic Wave Packet in the Northern Hemisphere Summer Season

利用NCEP/NCAR再分析资料,使用局地能量诊断和三维准地转波动通量等工具分析了2002年北半球夏季的一次斜压波包过程。结果表明:波包发展的能量来源主要依靠斜压转换获得,频散项对波包的影响很小;波包进入衰减期以后,波包的东侧和南侧作为垂直方向的波动源,向下传播波动通量;向下的波通量进入对流层低层气旋范围,对气旋的维持起到重要作用。

Using NCEP/NCAR reanalysis data and diagnosis of local kinetic energy and 3-dimensional quasi-geostrophic waveactivity fluxes, the author carried out a case study of baroclinic wave packets in the northern hemisphere summer season of 2002. The result indicates that the energy source of packet development is through baroclinic conversion, and dispersion term has little effect on wave packets ; when wave packet turns into its attenuation period, the eastern and southern parts of wave packets become wave source in the vertical direction;the downward wave activity fluxes propagate into the cyclone in lower troposphere and helps maintain the cyclone.